A host (an information processing apparatus), such as a server, and an input and output device (I/O device) are necessarily installed within a distance of approximately 100 m from each other for a Block Multiplexer Channel (BMC) connection that is used for an electric cable, and within a distance of several kilometers from each other for an Optical Channel LINK (OCLINK) connection that is used for an optical fiber cable. In contrast, there is a system in which a communication channel between the host (the information processing apparatus) and the input and output device (I/O device) is extended using an extension device (a relay device), and thus, utilization between long-distance points is made possible.
In this system, the host and the extension device are coupled via a network, such as a wide area Ethernet (a registered trademark) that uses a Transmission Control Protocol/Internet Protocol (TCP/IP), which does not have a distance limitation, and the extension device and the I/O device are coupled through an FCLINK connection or the like, which has the distance limitation. The FCLINK connection employs a connection scheme in compliance with Fibre Channel (FC)-Single Byte (SB)-2 standard. Accordingly, the utilization between the long-distance points, between which the host and the I/O device are positioned by a long distance, is possible.
Japanese Laid-open Patent Publication Nos. 2004-164490 and 2007-115138 are examples of the related art.